The Corps of Volunteers for Northwest Discovery (Lewis & Clark Expedition) passed through the Tri-Cities area in October of 1805 and again on their return trip in April, 1806. It was at the confluence of the Snake and Columbia Rivers that the Expedition knew, for the first time since entering uncharted territory, exactly where they were. Today, the three rivers of the Snake, Columbia and Yakima, and the three cities of Pasco, Kennewick and Richland are intrinsically linked, forming a vibrant urban and recreational hub at the center of Washington's Columbia Plateau.

Richland started as a small farming community, but the population exploded from less than 2,000 to more than 51,000 residents in 1943 when the government built the country's first nuclear reactor on the Hanford Site. Once a secret city where atomic bomb workers quietly did research, Hanford still plays a major role in the Tri-Cities economy and is a huge part of the science and technology communities worldwide. The Hanford Reach, just north of town, is the last free-flowing stretch of the Columbia River in the United States and was designated a National Monument by President Clinton.

To the south, Kennewick is the largest of the Tri-Cities, sharing a border with Richland and an architecturally magnificent cable bridge, which is lighted at night, with Pasco. The city is known as southeast Washington's retail center and its Columbia Park is the scene for the July Columbia Cup Unlimited Hydroplane Races.

East of Richland, Pasco has strong agricultural roots and a diverse population with about half Hispanic residents. Their open air Farmers' Market is one of the largest in the state. The arrival of the Northern Pacific Railroad was instrumental in bringing a rush of settlers to Pasco so it is fitting that the town hosts one of the best railroad museums. Pasco is also home to the first commercial airport west of the Mississippi.

Together, the three distinct cities and outlying areas offer a multitude of recreational, cultural and historical activities that include premier, year-round golf courses, award winning wineries, museums, first-class shopping and abundant water recreation.